33-Converting to an open cooling system

[fiatslug87]

If anyone has this please post.

[hgeranium]

Cruiser never made an official writeup for this but through multiple posts he and others gave enough information. I'll try my best to compress the information so this topic is a one-stop-shop for curious onlookers and link all the threads at the end.

 

The method that cruiser toyed around with involves retaining the closed renix radiator, but adding an inline radiator hose filler, an overflow tank, and a couple of molded heater hoses. The part numbers are here: 

11038 heater hose

11039 heater hose

63745 Moroso inline rad hose filler (on the upper rad hose)

730-4514 2.5 reservoir (7304514 is an alternative, just depends on where you can fit the tank; the closer to the moroso the better!)

703-1698 rad cap

He also mentions that, while you're doing this, you can switch to "97 [heater] hoses [to] get rid of all that mumbo jumbo crap of the Renix hoses.", although not necessary. It's an easy way to delete the HCV with minimal work.

^ This is cruiser's picture using the 7304154 NAPA overflow tank. There is another example that I will put below. 

"Used a tank from a Cherokee and placed it where the old one was."

Moroso

Example of the 2.5 coolant tank as overflow below vvvv; bolts right in.

You can also reuse the expansion tank as overflow: "Cleanest and easiest install IMO is to repurpose existing pressure bottle with $5 worth of parts. You don't have to relocate fuel pump ballast resistor or anything else on driver side fender. A couple of clamps and a nylon reducer and the pressure tank becomes the overflow bottle. "

 

Another, albeit more expensive, method involves simply installing a Macs coolant tank and the 2.5 overflow tank, as done by PIKE: 

However, the moroso serves the same purpose as the macs, but at a much cheaper price; just requires a few more parts.

 

 

If I'm missing something or get something completely wrong please tell me in the comments! I haven't done this myself so if anyone that has experience can make a step-by-step guide, that would greatly help the cohesiveness of this jumbled mess of a post lol. For some, it may be easier to just go through all the posts that I linked.

 

[OzarkGuy]

Ok, I am new here and I am sure this subject was beaten to a pulp... That said as an ignorant fool that I am, what does the open system do over a factory set up? Is it worth it for a 2wd truck? Thanks!

[Pete M]

14 minutes ago, OzarkGuy said:

Ok, I am new here and I am sure this subject was beaten to a pulp... That said as an ignorant fool that I am, what does the open system do over a factory set up? Is it worth it for a 2wd truck? Thanks!

 

most importantly it eliminates the complicated, failure-prone valve setup.   also means coolant is always flowing through the heater core which reduces the chance of sludge buildup. 

[OzarkGuy]

8 minutes ago, Pete M said:

 

most importantly it eliminates the complicated, failure-prone valve setup.   also means coolant is always flowing through the heater core which reduces the chance of sludge buildup. 

Ok, that makes sense. I was thinking this was an "open atmospheric" kind of thing. I know the heater valve was replaced recently by the previous owner. I was looking to replace the metal "F" coolant pipe but see those have been discontinued. I know guys just make up a replacement out of hoses and T's but I like originality. That said, when I eventually get to pulling the engine out for detailing I may just eliminate a bunch of that stuff and add an electric supplemental fan to the rad. My truck has no A/C from factory. I find it amazing that one little clutch fan keeps this thing cool leaving half the rad un-fanned!

 

[Pete M]

14 minutes ago, OzarkGuy said:

Ok, that makes sense. I was thinking this was an "open atmospheric" kind of thing. I know the heater valve was replaced recently by the previous owner. I was looking to replace the metal "F" coolant pipe but see those have been discontinued. I know guys just make up a replacement out of hoses and T's but I like originality. That said, when I eventually get to pulling the engine out for detailing I may just eliminate a bunch of that stuff and add an electric supplemental fan to the rad. My truck has no A/C from factory. I find it amazing that one little clutch fan keeps this thing cool leaving half the rad un-fanned!

 

 

this lil guy?  https://www.partsgeek.com/l2wggl7-jeep-cherokee-heater-valve.html

 

[Eagle_SX4]

17 minutes ago, OzarkGuy said:

I was looking to replace the metal "F" coolant pipe but see those have been discontinued.

I have one I pulled off my truck that is rust free. If you want it PM me and we can work something out.

[Pete M]

you can get the flushing benefit if you simply turn the heat on now and again.  especially first thing when you fire up the truck so you're not baking yourself in the summertime  

[OzarkGuy]

13 minutes ago, Pete M said:

you can get the flushing benefit if you simply turn the heat on now and again.  especially first thing when you fire up the truck so you're not baking yourself in the summertime  

 I get it why people remove the valve but with a truck that has no A/C, I would rather try to keep the residual heat away from the interior! My wife thought I was crazy to buy something with no A/C. At first I was thinking about retrofitting in a stock system but the more I thought about it, I am not into making this more complex. We left AZ two years ago and living in SouthWest MO, the humidity and temps are nowhere near my upper tolerance levels!

 

[Pete M]

every single XJ 97+ has the valve removed, whether with or without AC.   Jeep themselves eventually got sick of it